A certain amount of emulsifier is added into the polymer latex prepared by the traditional method. The emulsifier is a kind of surfactant. However, the stabilizer added when mixing with cement is also a kind of surfactant. As we all know, surfactant is easy to foam after mixing, especially after mixing with water, so a large number of bubbles will be generated when the cement slurry is prepared with severe stirring. However, the existence of a large number of bubbles is likely to reduce the density of the cement slurry, and eventually cause adverse effects on the comprehensive properties of the oil well cement slurry, such as filtration, gas channeling resistance and low compressive strength . As mentioned earlier, the bubbles in latex cement slurry are mainly produced by the surfactant which is agitated vigorously. The bubble wall of this bubble is thick, and ordinary defoamer is difficult to eliminate. Especially when the surfactant containing relatively large dosage is used, the development of a defoamer which can effectively reduce foam is obvious when developing additives that are compatible with latex cement slurry system. It's very important to have a good job. In the current construction, the bubbles in the cement slurry system are usually reduced by slowly mixing the cement slurry, but it is time-consuming and laborious, which is not conducive to the smooth cementing operation.

Traditional latex cement still has poor water resistance. The reason may be that polymer dispersion is suspended in water by 0.05~0.5 m polymer particles, and polymer particles are hydrophobic. It is because emulsifiers are added to make the emulsion suspension system stable. If the cement stone is immersed in water for a long time, the residual emulsifier in the cement stone will slowly have hydrophilic and surface active effects when it meets with water, which will lead to the swelling, softening, strength reduction and other adverse consequences of the cement stone.

Latex oil well cement toughening agent is the focus of research at home and abroad, because our work also develops latex suitable for oil well cement toughening as the main content of toughening agent. In view of the disadvantages of latex toughening agents in such aspects as high temperature resistance, salt tolerance, shear resistance, water resistance and stability, we consider introducing a monomer which can improve polymerization, high temperature resistance, salt tolerance, shear resistance and stability of emulsion. Nowadays, 2-acrylamide-2-methylpropanesulfonamide (AMPS) is a hot research topic in polymer oil well cement admixtures.

At present, some domestic research institutions have begun to develop this kind of latex toughening agent, but due to the limitations of many factors and the immature technology, the application of this kind of admixture is not wide enough. Traditional latex additives as additives in oil well cement will cause excessive foaming of cement slurry and the addition of defoamer. The softening of cement paste and the decrease of strength will be due to the addition of emulsifiers in the process of traditional latex synthesis. At present, there is a polymerization method that can be used to synthesize latex without adding emulsifier. Soap free emulsion polymerization can solve this problem very well.